In piping systems, there is a variety of ways to connect or join two separate lengths of pipe. In general, connections between two lengths of pipe traditionally have been achieved through one of four ways: (1) gluing or cementing; (2) welding; (3) threading; or (4) external connections such as collars and flanges. In gluing or cementing, an adhesive is applied to the male end, to the female end, or to both ends of the pipes being joined. The male end of one pipe is inserted into the female end of the adjacent pipe being joined and the adhesive cures, permanently joining the pipes. With welding, two metal pipes are joined using molten metal. In threading, the male end of a pipe has external threads and the female end of the adjacent pipe has internal threads. The male end is inserted into the female end of the adjacent pipe, the pipes are rotated, and the threads engage each other. With external connections such as collars and flanges, some sort of threaded fastener interacts with the external connecting structure to securely lock the connection between the two pipes.
Each of the aforementioned connection types has certain disadvantages. For example, a glued or cemented connection can be cumbersome and time consuming. The pipe surfaces must be cleaned and the adhesive applied and allowed to cure before the connection can withstand tensile force. Further, the pipes cannot be disconnected without destruction of at least a portion of the pipe. In threaded connections, the connection can be achieved quicker and the pipes usually can be disconnected and reused, but threaded connections typically cannot withstand high tensile forces. In addition, threaded connections can be cross-threaded relatively easily and require tools to grip, hold, and turn the pipes. Welded connections can withstand significant tensile forces but can only be used on metal pipes. Further, creating the weld is a time-consuming task, and, once the weld is formed it is difficult to remove and may not be possible without pipe destruction. With external connections, the connection often can be removed and can withstand significant tensile forces, but forming the connection is also a time-consuming task.
Accordingly, there is a need for a pipe coupling that allows a connection that will withstand large tensile forces, can be quickly formed with similar adjacent pipes, and can be easily disconnected with the proper tool, regardless of the material from which the pipe is made.